I need help please because I cannot find a solution for my problem.

I need to hide a subfolder in the url of my wordpress site.

I created a subfolder where I uploaded some static pages in php

Example: domain/subfolder/file.php

What I need is remove/hide "subfolder" to get the next:

domain/file.php

I tried many htaccess codes I found here but I always get a 404 error.

Thanks in advance for your help.